There is a service, which allows plural users to use applications prepared on a server connected to the Internet. In such a service, the way to combine programs on the server (the way to use when viewed from the user) is previously determined by a provider of the service, and the user cannot freely combine the plural programs on the server to use them.
For example, JP-A-2000-236326 discloses a technique not to require the maintenance of the software, and not to require controls or the like relating to the activation of the software at a time when the intercommunication service is utilized. Specifically, clients are defined as thin client terminals having minimum modules for server accesses and personal authentication, and servers are defined as a managing server having a common middleware necessary for operations of the thin client terminal, an application software and a management program to manage those, and an authentication server to carry out the personal authentication with the thin client terminals. Each of the thin client terminals downloads necessary software from the management server when the power supply is turned on and when the service is utilized. Only by downloading necessary programs to the client, various services cannot be provided.
In addition, for example, JP-A-2000-347958 discloses a technique to reduce the data communication amount and to save a used capacity of a computer memory. Specifically, a server stores programs to be provided for clients in a form in which the programs are divided into respective functions. Therefore, the clients can select programs stored in the form in which the programs are divided into respective functions by each necessary function. Then, only the selected programs are provided for the client from the server. By this configuration, it is possible to select and download only a print control program concerning the necessary functions to the client. Accordingly, it is possible to reduce the data communication amount from the server to the client, and to save the used capacity of the computer memory. This technique is not characterized in a combination of programs defined by the client.
Furthermore, US-2002-0073145-A discloses a technique to download programs with a small amount of data to a client terminal from a server to cause the programs to execute a desired data processing. Specifically, definition information is inputted by the client terminal, the server reads out setting information corresponding to the definition information and transmits it to the client terminal, and one or plural functional parts are called on the basis of the setting information. The functional part is such that plural data processings are divided into common unit processings, and a processing logic extracted from those is described. The client terminal or the processing server dynamically generates a unit processing program by the processing logic based on one or plural functional parts, and executes the one or plural generated unit processing programs in accordance with conditions based on the setting information. In this technique, there is no viewpoint such as authorization of the unit processing program. Besides, there is no disclosure on a problem in a case where plural kinds of unit processing programs are executed.
In the related art as described above, when the client side combines arbitrary functions prepared on the server side and the client side receives, through a network, the provision of a specific service realized by the combination of the functions, consideration is not given to the judgment as to whether or not the service can be provided, and the discrimination between plural kinds of combinations. Accordingly, in the related art, there is a problem in the flexible and suitable provision of the network service.